Smoking product with improved flavor and method of making it

ABSTRACT

A smoking product including a substantial proportion of tobacco stem material and incorporating carbamide and a saturated fatty acid composition having a carbon chain length of 16-18. The carbamide is present in an amount from 1.0 to 3.0 percent and the fatty acid is present in an amount of from 1.0 to 4.0 percent, by weight, of the stem material. The carbamide and fatty acid impart to the stem material, when it burns, some of the more pleasant taste and smell characteristics of burning tobacco leaf. The stem material may be in its natural state, but crushed, or it may be made into a reconstituted sheet or film.

United States Patent 11 1 Stevens et al.

SMOKING PRODUCT WITI-I IMPROVED FLAVOR AND METHOD OF MAKING ITInventors: Chester U. Stevens; William A.

Selke, both of Stockbridge, Mass.

Assignee: Kimberly-Clark Corporation, Nee

nah, Wis.

Filed: Mar. 22, 1971 Appl. No.: 126,967

US. Cl. ..l3l/17, 131/2, 131/144,

131/140 C Int. Cl. ...A24b 03/14, A24b 15/04, A24b 03/12 Field ofSearch..13l/17, 140-144 References Cited UNITED STATES PATENTS 9/1971 Briskinet a1. 1 31/2 1/1967 Osborneetal ..131/140C 3,298,378 1/1967 Stevens eta1 ..131 140 c 3,464,422 9/1969 Light et al v ..131/140 c 2,576,02111/1951 Koree ..131/2 Primary Examiner-Melvin D. ReinAttorney-Breitenfeld & Levine [57] ABSTRACT A smoking product includinga substantial proportion of tobacco stem material and incorporatingcarbamide and a saturated fatty acid composition having a carbon chainlength of 16-18. The carbamide is present in an amount from 1.0 to 3.0percent and the fatty acid is present in an amount of from 1.0 to 4.0percent, by weight, of the stem material. The carbamide and fatty acidimpart to the stem material, when it burns, some of the more pleasanttaste and smell characteristics of burning tobacco leaf. The stemmaterial may be in its natural state, but crushed, or it may be madeinto a reconstituted sheet or film.

7 Claims, No Drawings SMOKING PRODUCT WITH IMPROVED FLAVOR AND METHOD OFMAKING IT This invention relates generally to tobacco, and has ratedfatty acids and carbamide are non-toxic and harmless, and are compatiblewith tobacco and with substances commonly employed in the preparation ofarticles for smoking. For these reasons they have been particularreference to making products having im- 5 found to be admirably suitableas additives to tobacco proved smoking qualities, and to a method ofmaking and tobacco products. Their employment is practically suchproducts. feasible, and allows tobacco stems to be used in larger Theterm Smoking produc is intended to in proportions by making up for thenatural deficiencies within its scope all known media, such as cigars,of such stems as contributors to smoking values. cigarettes, Smok ngtoba co, em, for j ying the Moreover, addition of the fatty acids andcarbamide ar m and flavor ofbunling tobacco beneficiates both the mainand the side streams of h? desirable flavor and Smell of burning tobaccois smoking tobacco. By main stream" reference is made derived Primarilym the Products of Py y g to the smoke traveling directly into thesmokers d r d y h Smooth laminar p r of the leaves of mouth, and by sidestream" is meant the smoke the tobacco plant. The midribs of the leaves,commonly emanating directly from the burning tobacco product. butinaccurately referred to in the trade as stems", are A more particularobject of the invention is to prodeficient in producing the sameeffects. Burning stem vide an economical and commercially practicalportions produce a flat smoke and contribute only a procedure by meansof which the fatty acid and carbah y aromatic touchmide can beadvantageously incorporated in tobacco For the sake of simplicity, thesmooth portions of the products for the intended purpose. leaves will bereferred to hereinafter as leaf" and the The following flow diagram isillustrative of a midribs will be r f rred to as stems. procedure thathas been found to be useful and Some tobacco products, notably sheetedtobacco satisfactory:

NATURAL SOLVENT TOBACCO EXTRACT STEMS CONCENTRATION L FIBROUS RESIDUESATURATED r- FATTY ACID WATER BEA'IER I AND CARBAMIDE Jr SHEETED TOBACCOPRODUCT materials, contain appreciable and sometimes predominantproportions of natural tobacco stems. It is an object of this inventionto improve the smoking qualities need not be Composed exclusively ofStems but y of such products. Coordinately, it is an objective of theinvention to impart enhanced desirable aroma and flavor to articles forsmoking whose composition includes, or may consist essentially of,fragments of natural tobacco stems.

clude leaves or fragments of leaves in any desired proportion. Thesolvent employed to produce the extract, and leave a fibrous residue, isusually and preferably water but is not necessarily or exclusivelyaqueous. The

beater employed is part of known papermaking equipment, and the fibrousresidue is adequately comminuted so as to be employable like paper pulpin producing a slurry or suspension from which a paperlike web isproduced in accordance with conventional papermaking techniques. Theextract from the original.

product is first concentrated and may then be treated, if desired, invarious ways (not shown) to alter or improve its composition. Finally itis introduced into the paperlike web, by any desired spraying orapplicator or other suitable procedure, and the sheet is then dried.

The result is an artificial fibrous sheeted tobacco product which can beused in sheet form, or can be shredded and then used, in the ultimateproduction of articles for smoking.

The fatty acid and carbamide are preferably introduced, as indicated,either to the liquid concentrate prior to its application to the web, orto the web itself prior to the final drying procedure. However, othermethods of incorporating these additives may be employed if desired. Forintroducing the additives, a soluble soap of the fatty acid can be madewith potassium hydroxide, soda, or ammonium hydroxide in the usual way.The requisite carbamide may be combined in water solution with the fattyacid soap (potassium soap preferred). Alternatively, the fatty acid andcarbamide can be dissolved in a volatile organic solvent, such asacetone.

The amount of the additives required to produce the desiredbeneficiating effect is relatively small. The addition of from 1.0 to 4percent, by weight, of fatty acid and from 1.0 to 3.0 percent, byweight, of carbamide, to tobacco stems, in whatever form they may beemployed, has proven satisfactory. Thus, in cases where the stems aremade into a sheeted product, and where the fibrous part of the sheet iscomposed chiefly of such stems, the fatty acid is preferably introducedin an amount equal to from 1.0 to 4 percent of the sheet, by weight, andthe carbamide is preferably introduced in an amount equal to from 1.0 to3.0 percent of the sheet, by weight. If the fatty acid and carbamide areadded in lesser amounts than mentioned above, the effect isunnoticeable. If a greater proportion of fatty acid than mentioned isemployed, the smoke tends to take on a waxy note, and if a greaterproportion of carbamide is used the smoke becomes ammoniacal.

ln converting sheeted tobacco material containing fatty acid andcarbamide to the form of an article for smoking, it may be combined inany desired proportion (and in sheet or shredded form) with naturaltobacco. In some cases, it may be used entirely alone.

However, as is well known, the production of smoking tobacco andarticles for smoking does not necessarily involve the employment of anartificial sheeted tobacco material of the character described. Whateverthe form or nature of the tobacco product may be, if natural tobaccostem material is present in any amount, and if it is desired tocompensate for its deficiencies as a creator of desirable pyrolysisproducts, saturated fatty acid and carbamide can be used as additives.Their manner of use can be varied, as may be desired, e.g., thecarbamide and fatty acid soap solution could be sprayed onto orotherwise applied to tobacco leaves or into intermixture with a shreddedtobacco product, or they could be used as an ingredient of otheradditives customarily employed. 1f reconstituted tobacco is being madeby the cast film process, wherein powdered tobacco in a binder isextruded as a film and then dried, the carbamide and fatty acid soapsolution may be mixed with the tobacco and binder prior to casting. Theproportion of fatty acid and carbamide to be used are dependent in eachcase upon the amount of stems or stem derivatives present.

The mode of action of the fatty acid, for which palmitic acid ispreferred, is in part that of supplying a material whose pyrolysisproducts apparently contribute a milder smoke flavor. The overall effectis best when a commercially pure palmitic acid is used (100 percentsaturated fatty acid, not over 10 percent C-1 8 present). Use of alarger percent of C-18 saturated fatty acid, or saturated fatty acidhaving a carbon chain length less than 16, leads to a waxy taste in thesmoke when optimum amounts of the mixture are incorporated in thetobacco. The shorter chain fatty acids give an off flavor to the smokewhen more than a trace is present and similarly the unsaturated fattyacids lead to undesirable flavors, particularly on storage for a time.

Carbamide does contribute some ammonia to the smoke which has thecapability of reacting with some of the low molecular weight acidsgenerated during combustion. Carbamide also has the capacity to reducethe concentration of aldehydes which are generated by combustion ofcellulose and are suspected of being a major contributor to theextremely sharp and acrid smell of burning cellulose.

When used together, the fatty acid and carbamide show synergism,possibly since the ammonia incidentally released by pyrolyzing carbamidecan react with acidic fragments formed from the fatty acid as well asfrom carbohydrates present. Whatever the mechanism, the smoke flavor hasbeen found milder and preferable when addition of carbamide and fattyacid has been made to blends high in stems.

The preceding explanation is intended to suggest ways in which theobserved action can occur but is not intended to limit the disclosure tothese precise reactions.

The following examples are illustrative:

EXAMPLE 1 A mixture of lamina scrap, tobacco dust, and stems, consistingof approximately percent stem and 25 percent leaf, was extracted withwater in accordance with the process described and the fibrous residuewas beaten and formed into a paper-like sheet by ordinary papermakingtechniques. Meanwhile, the extract was concentrated by evaporation toabout 45 percent solids, and to it was added controlled amounts of thefatty acid as a potassium soap and carbamide. The fatty acid employedwas commercially available extra pure palmitic acid, which upon analysiswas found to contain percent palmitic acid (C-l6) and 5 percent stearicacid (C-1 8). The extract with the additives was introduced into thesheet by means ofa size press. The amount of extract added wascontrolled so that the amount of extractables in the dried final productwas about 50 percent, the concentration of the fatty acid being 3.35percent, by weight, of the stem portion of the reconstituted tobaccosheet, and the concentration of carbamide being 2 percent, by weight, ofthe stem portion of the reconstituted tobacco sheet.

As a control, reconstituted tobacco was made exactly as described above,except no fatty acid or carbamide were added to the extract.

Both sheets were shredded and made into cigarettes. When smoked by apanel of testers, cigarettes containing the additives were found to haveexcellent flavor, whereas cigarettes without the additives were harsh.

EXAMPLE II Reconstituted tobacco was made according to the proceduredescribed in Example 1, except that pure palmitic acid was used, havingan analysis of 90 percent palmitic acid (C-1 6) and 10 percent stearic(C-l8), in place of extra pure palmitic acid. Cigarettes made from thistobacco had excellent flavor, equal to that of the cigarettes of ExampleI.

EXAMPLE Ill Reconstituted tobacco was made according to the proceduredescribed in Example I, except that food grade" palmitic acid was used,having an analysis of 70 percent palmitic acid (C-16), 25 percentstearic acid (Cl8), and 5 percent other saturated fatty acids, in placeof extra pure palmitic acid. Cigarettes made from this tobacco hadflavor almost as good as the cigarettes of Examples I and Il.

EXAMPLES IV Vl Reconstituted tobaccos were made according to theprocedure described in Example 1, except that the fatty acids listedbelow were used in place of-extra pure palmitic acid. Cigaret es madefrom the tobaccos were characterized as indicated on the following list:

Cigarette Quality Fatty Acid Actual Analysis Stearic Acid Stearic Acid Cl8-40% Not quite as Double Pressed" Palmitic Acid C l 6-50% Flavorful asOt e saturated fa y EXAMPLE VII Natural tobacco fragments containingabout .60 percent stems were powdered to such a degree that all passedthrough a 20 mesh (Le, 20 openings per linear inch), screen and asubstantial part through a 40 mesh screen. To 500 parts of a 2 percentsolution of methyl cellulose, used as a binder, was added 0.7 partscarbaf mide and 0.9 parts potassium palmitate. One hundred parts of thepowdered tobacco was mixed into the solution, producing a pastydisperson. The latter was spread to form a film of such thickness thatafter drying in a stream of warm air to a moisture content of aboutpercent a dry film was obtained which approximated the thickness andweight of natural tobacco. The carbamide content of ,the film was 1.1percent, by weight, of the stem portion, and the fatty acid content was1.2 percent, by weight, of the stem portion.

The reconstituted sheet was shredded and made into cigarettes whoseflavor and mildness were superior to cigarettes made from reconstitutedtobacco made as described above but without the addition of carbamideand potassium palmitate.

EXAMPLE Vlll were then blended with leaf shreds, the stems beingExamples l and ll percent of the final mix. Cigarettes made from thisblend were again preferred by the smoking panel over those made from thesame blend using untreated crushed stems.

Obviously a similar result can be reached by spraying acarbamide-palmitic acid solution on the blended mix in Example Vlllrather than on the stems alone.

A reconstituted sheet for use as a little cigar wrapper or a bindersheet for cigars can be made by the same techniques outlined in ExamplesI-VII. In these cases, particularly in the little-cigar wrapper sheet,some wood fiber may be added to the tobacco sheet to strengthen it, butat the same time increasing the need for smoke flavor improvement. Anillustration follows:

EXAMPLE IX Following the procedure used in Example I with a mixture ofcigar tobacco of which percent was stem and 30 percent lamina, 20percent un-bleached kraft pulp was added to the fibrous residue. To theconcentrated extract was added enough palmitic acid soap and carbamideto give 1 percent palmitic acid and 4 percent carbamide, bothpercentages being by weight of the stems and kraft pulp portion of thereconstituted sheet. This sheet was tested by shredding and forming intocigarettes. All of the smokers preferred the cigarettes with thecarbamide-palmitic additives to cigarettes which were identical exceptfor the absence of the additives.

EXAMPLE X Following the procedure of Example IX a product was made withonly the 4 percent carbamide added. Evaluation of this indicated a mildbut slightly ammoniacal, flavor.

EXAMPLE XI Following the procedure of Example ll but adding only 2.5percent palmitic acid as the potassium soap to the reconstituted sheetgave a product that the smokers found better than the control but not asgood as that of Example 11.

The last two examples reflect the synergism present when fatty acid andcarbamide are used.

The invention has been shown and described in preferred form only, andby way of example, and many variations may be made in the inventionwhich will still be comprised within its spirit. It is understood,therefore, that the invention is not limited to any specific form orembodiment except insofar as such limitations are included in theappended claims.

What is claimed is:

1. A smoking product comprising a tobacco composition which includes asubstantial proportion of tobacco stem material whose tasteandaroma-generating characteristics, when burned, are inferior to those ofburning tobacco leaf lamina, said tobacco composition includingcarbarnide and a saturated fatty acid composition having a carbon chainlength of l6-l8, said carbamide being present in an amount from 1.0 to3.0 percent, by weight, of the stem material, and said fatty acidcomposition being present in an amount from 1.0 to 4.0 percent, byweight, of the stem material, said ,carbamide and fatty acid impartingto the stem material, when it burns, some of characteristic taste andsmell of burning tobacco leaf lamina.

2. A smoking product as defined in claim 1 wherein said fatty acidcomposition is essentially palmitic acid.

3. A smoking product as defined in claim I wherein said tobaccocomposition also includes non-tobacco cellulosic material, saidcarbamide being present in an amount from 1.0 to 3.0 percent, by weight,of the combined stem and non-tobacco cellulosic material, and said fattyacid composition being present in an amount from L to 4.0 percent, byweight, of the combined stem and non-tobacco cellulosic material.

4. A smoking product as defined in claim 1 wherein said tobaccocomposition comprises an intermixture of natural tobacco andreconstituted tobacco.

5. A smoking product as defined in claim 1 wherein said tobaccocomposition is essentially natural tobacco.

6. A smoking product as defined in claim 1 wherein al, whereby saidtreated stern material, when it burns,

has imparted to it some of the characteristic taste and smell of burningtobacco leaf lamina.

2. A smoking product as defined in claim 1 wherein said fatty acidcomposition is essentially palmitic acid.
 3. A smoking product asdefined in claim 1 wherein said tobacco composition also includesnon-tobacco cellulosic material, said carbamide being present in anamount from 1.0 to 3.0 percent, by weight, of the combined stem andnon-tobacco cellulosic material, and said fatty acid composition beingpresent in an amount from 1.0 to 4.0 percent, by weight, of the combinedstem and non-tobacco cellulosic material.
 4. A smoking product asdefined in claim 1 wherein said tobacco composition comprises anintermixture of natural tobacco and reconstituted tobacco.
 5. A smokingproduct as defined in claim 1 wherein said tobacco composition isessentially natural tobacco.
 6. A smoking product as defined in claim 1wherein said tobacco composition is essentially reconstituted tobacco.7. A method of making a smoking product, comprising the steps ofproviding a tobacco composition which includes a substantial proportionof tobacco stem material, and combining with said stem materialcarbamide and a saturated fatty acid having a carbon chain lEngth of16-18, said carbamide being present in an amount from 1.0 to 3.0percent, by weight, of the stem material, and said fatty acid beingpresent in an amount from 1.0 to 4.0 percent, by weight, of the stemmaterial, whereby said treated stem material, when it burns, hasimparted to it some of the characteristic taste and smell of burningtobacco leaf lamina.